The transmitting of data over the internet continues to increase in significance. The internet is a global data network or, expressed more precisely, comprises a plurality of different data networks interconnected my means of, for example, what are termed routers.
In each case one or more central computers, referred to in the relevant literature frequently as servers, communicate within the internet with clients located remotely from them, for example with a (stationary or portable) computer, a telephone, etc., and/or with further, central computers. Communication takes place using what are termed internet protocols, in particular the TCP/IP Protocol (Transmission Control Protocol/Internet Protocol). Software (what is termed a socket or TCP/IP stack) able to understand and evaluate the TCP/IP Protocol is loaded for this purpose on, for example, the respective client.
An increasing number of private data networks, which is to say data networks that can only be used by specific, authorized persons, are based on the technology and concept of the internet. Data networks of said type are referred to in the relevant literature as intranets. Within an intranet, in a manner analogous to the internet a relevant central computer, for example, communicates using internet protocols, in particular the TCP/IP Protocol, with clients located remotely from it, for example (stationary or portable) computers, telephones, etc. (and/or with further, central computers). For transmission, the relevant intranet data is divided in each case into individual packets then sent in an asynchronous manner.
Intranets are generally connected to the telephone network via the relevant, central computer, so are able to communicate with a further computer over the telephone network.
Data communication over the telephone network can take place on the basis of, for example, POTS (Plain Old Telephone Service) data transmission protocols or ISDN (Integrated Services Digital Network) data transmission protocols; alternatively on the basis of xDSL (x Digital Subscriber Line) data transmission protocols, for example by means of ADSL (ADSL=Asynchronous Digital Subscriber Line) data transmission. A plurality of frequency bands are employed in the case of data communication according to an xDSL protocol which are above the frequency bands used for POTS data transmission or, as the case may be, ISDN data transmission.
If the software loaded on a central intranet computer is to be updated, a further computer that initiates software updating can establish a POTS connection or an ISDN connection to the central intranet computer over the telephone network then transmit the software files required for updating to said central intranet computer.
The central intranet computer, and hence also the intranet clients connected thereto, for example the above-cited computers, telephones, etc. (and/or the further central computers connected to the central intranet computer) can additionally also be connected to the internet. The relevant central intranet computer can herein, for example, be continually connected to the internet (which is to say always on line). Central intranet computers of said type or, as the case may be, the intranet clients connected thereto have as a rule permanent IP (Internet Protocol) addresses consisting of a multi-digit number. Via the relevant address, other computers connected to the internet can establish a connection to the central intranet computer or, as the case may be, to the intranet clients connected thereto.
Other central intranet computers are not continually connected to the internet (which is to say are not always on line). Said computers or, as the case may be, the intranet clients connected thereto will be able to receive a temporary IP address assigned by the respective central (or any other) computer if they establish a connection to the internet (using, for example, a POTS, ISDN, or xDSL data transmission protocol) with, for instance, a corresponding central computer of an internet provider having been intermediately connected. Unlike in conventional telephone networks, there is thus in this case no fixed assignment between the respective device (here: the relevant central computer or, as the case may be, intranet client) and the call identification (here: an IP address consisting of a multi-digit number).